The Italian was brought in as caretaker manager at Stamford Bridge after Andre Villas-Boas' poor start to the campaign and following a loss at the the Hawthorns.
Di Matteo, who had previously managed the Baggies was then summoned by Roman Abramovich and given the role until the end of the year.
The 42 year-old went on to win the FA Cup and Champions League double, leading to him being installed in the job on a more permanent basis.
Today marks the first return of the Blues to the Hawthorns and the European Champions might night have it all their own way with Steve Clarke's side looking a tough outfit at this stage of the campaign.
Asked if he had been expecting the boot, he said: "I did, yeah, quite frankly. It was a very emotional day, that day, for us."
"You need to put things into perspective,"
"We're in good shape, the players are in good spirit. We need to keep going on and try to get the win.
"We've shown our character many, many times. It's not just a test of character. When we play well and manage to do so in a game, we can win games."